[1] Childrens Mem Hosp, Div Pediat Dermatol, Chicago, IL USA
[2] Evanston NW Healthcare, Ctr Outcomes Res & Educ, Evanston, IL USA
[3] Univ Calif San Francisco, Dept Dermatol, San Francisco, CA 94143 USA
[4] San Francisco Vet Affairs Med Ctr, San Francisco, CA USA